Assessment of Chemotherapy Response in Colorectal Cancer Using PET-CT Versus DWI-MRI

Area of Science:

• Oncology
• Radiology
• Medical Imaging

Background:

• Conventional imaging challenges in assessing colorectal cancer treatment efficacy.
• Need for advanced imaging techniques to monitor chemotherapy response.

Purpose of the Study:

• Compare diagnostic effectiveness of integrated PET-CT and DWI-MRI for colorectal cancer chemotherapy response.
• Evaluate PET-CT vs. DWI-MRI in monitoring treatment in colorectal cancer patients.

Main Methods:

• Prospective comparative analysis of 132 colorectal cancer patients undergoing first-line chemotherapy.
• Baseline and serial PET-CT and DWI-MRI scans at 3, 6, and 12 weeks.
• Assessment using RECIST v1.1, PERCIST v1.0, and apparent diffusion coefficient (ADC) analysis.

Main Results:

• DWI-MRI showed a significant ADC rise (51.4%) compared to SUVmax reduction (36.0%) with PET-CT (p < 0.001).
• Strong negative correlation between SUVmax and ADC values (r = -0.732, p < 0.001).
• DWI-MRI demonstrated higher diagnostic performance (AUC 0.887, sensitivity 90.9%, specificity 76.7%) than PET-CT.

Conclusions:

• Both PET-CT and DWI-MRI are effective for chemotherapy response assessment in colorectal cancer.
• DWI-MRI exhibits superior sensitivity and predictive accuracy, making it a preferred radiation-free option.
• Concordant responders to therapy showed significantly improved progression-free and overall survival.